1. Lesson 1 0x001 001 The Computer System Mohamed Zaki Principal Lecturer
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2. Main Topics What is a Computer? General-purpose & Dedicated Computers.
Computer as a system.
Computer hardware system.
Peripherals
Input Peripherals.
Output Peripherals.
Storage.
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3. Course Assessment Attendance & Contribution 10 Assignments (2) 20
Presentation
Midterm
Final 40
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4. What is a Computer?
Computer: is a programmable machine that receives input, stores and manipulates data/information, and provides output in a useful format.
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5. General Purpose and Dedicated Computers
General-Purpose computer solves many types of problems, such as (document typing, Drawing, games,..etc)
Dedicated Computers is used for only one task.
(Control process in the manufacturing industry)
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6. General Purpose and Dedicated Computers (cont.)
Remark: In general a dedicated computer is the same as a general-purpose computer in its fundamental construction
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7. Computer as a system
System: is a set of interrelated components working together to achieve a certain goal. So, to consider a computer as a system, the computer must contain related components working together to perform the main functions.
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8. Computer Components As a System
Computer System
Hardware
Software
Peripherals
Central
Processing
System
Programs
Application
Control Unit
ALU
Main Memory
Input Unit
Output Unit
Secondary
Storage
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9. 1-Computer Hardware
Hardware devices can be organized according to the following system functions:
Input: Devices that convert data into electronic form in the computer system.
Output: The output devices are used to convert the electronic information into a human understandable form.
Processing:  The CPU is the main processing component. ALU (Arithmetic Logic Unit) will perform all the processing.
Storage: Takes place in the primary storage unit of the CPU and in secondary storage units. these devices store data and program instructions are needed for processing.
Control: control unit of the CPU is the control component of the computer system. It interprets computer program instructions and transmits directions to other components of the computer system.
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10. Peripherals Parts of computer that transfer data in and out.
Input Peripherals.
Output Peripherals.
Secondary Storage.
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11. Input Peripherals: Devices used for transferring data from the outside world representation into the internal character code of the computer.
Keyboard.
Barcode reader: Barcode data can be described as a sequence of vertical lines vary in thickness, light focuses on and scanned across these lines using a small laser beam, then data can be read and input to computer.
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12. Other input peripherals:
Light pens }
Mice } Pointing devices
Touch screens. }
Digitizers.
Scanners.
Microphones.
Cameras.
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13. Output Peripherals Printers
1- Impact Printer: this method of printing is based on the impact of a hard object against an ink-coated ribbon, which is then forced on the paper to make it mark the shape of the character.
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14. Output peripherals (Impact Printers) (Cont.)
Line printers
Dot matrix printers
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15. Output peripherals (cont.) 2- Non-Impact Printers
Ink-jet printers.
Thermal printers.
Laser printers.
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16. Comparison between printers
Disadvantages
Advantages
Mechanism
Impact/Non-impact
Type
Low quality.
Used ordinary papers.
Not expensive.
It prints a whole line of text at one go.
Impact
Line printer
Low speed.
noisy
cheap
Use a pattern of dots in the shape of a character.
Dot Matrix
Ink is expensive compared with printer cost.
High speed.
Silent.
Colored
Sprays a stream of ink on an ordinary paper.
Non-impact
Ink-Jet
Slow.
Paper is costly.
Use heat to produce an image on special paper.
Thermal
Expensive
Large compared with others.
High quality.
A laser beam is used to dry up a powdered ink on the paper.
Laser
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17. Output peripherals (Cont.)
Plotters.
Visual Display Unit(VDU).
Projectors (Data Show)
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18. Secondary Storage Optical Storage Flash Memory - CD (Compact Disc)
- DVD (Digital Versatile Disc)
Flash Memory
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19. Storage Units
Bit (Binary Digit): it is the smallest unit to store data,(0 or 1).
Byte (B) :it is the basic storage unit of memory. It consists basically of 8 bits. It can hold one symbol only at a time.
Kilo Byte (KB)=1024 B
=210 B
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20. Storage Units of Memory
Mega Byte (MB)=1024 KB
=(1024 x 1024) B =104,8576 B
= More than a Million of bytes.
=210 x 210=220 B.
Giga Byte (GB)=1024 MB
=(1024 x 1024) KB
=(1024 x 1024 x1024) B
=104,8576 KB = 1,073,741,824 B
= More than a Billion of bytes.
=210 x 210 x 210 = 230 B.
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21. Storage Units * % 8 1024 1024 1024 1024 Bit Byte KByte MByte GByte
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22. Refreshing Questions
The ……………………. Can be described as an input device.
1.Light pen HP laser jet printer Plotter None
A device used for transferring a paper based image into a computer image is……………….
1. Ink jet printer 2. Scanner
3. Digitizer None
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23. Refreshing Questions (cont.)
RPM stands for _________.
DVD stands for _________.
VDU stands for _________.
10 MB =_____ KB.
Arrange the following in ascending order: 0.6GB, 840MB, 15000KB
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